% The addition of clonable features to feature models have increased the
% expressiveness of feature models, allowing the modelling of structural
% variability. Using clonable features we can model that, for instance, 
% automated houses have a variable number of floors and rooms. Nevertheless, 
% clonable features create new research challenges. Currently, some  
% state-of-art feature modelling tools are able to model and configure clonable % features. But, as the experienced reader probably knows, it is not always 
% possible to express all the relationships between features using feature 
% models. As a consequence, the the definition of external constraints, such as % mutual exclusion between features, is often required. Nevertheless, the 
% semantics of these state-of-art feature constraints become undefined when they % are applied to clonable features. In order to overcome this limitation, this 
% paper presents a new language for specifying external constraints between 
% features, which supports clonable features. We also explain how to 
% automatically determine if a given selection of features satisfies the 
% constraints expressed in this new language by means of translating these 
% constraints into a Constraint Satisfaction Problem (CSP). We validate our 
% ideas by applying them to a SmartHome software product line provided by 
% Siemens AG.

% Shorter version

% Clonable features increase the expressiveness of traditional feature models,
% allowing the modelling of structural variability. Using clonable features, we % can specify, for instance, automated houses have a variable number of floors
% and rooms.  it is not always possible to express all the relationships between % features using feature models. For instance, in a feature model for a
% SmartHome, a feature like Presence Simulation might require the selection of
% an Automatic Lights features. As a consequence, the definition of external
% constraints, such as A implies B, to capture these relationships is often
% required. Nevertheless, the semantics of these state-of-art external
% constraints become undefined when they are applied to clonable features.
